Super Best Audio Friends

Grados elicit strong reactions from the headphone community. Many readers may be too young to know that during the infancy of headphone audio, before the start of Head-Fi, and even for many years after, there were two big camps in headphones: Sennheiser vs. Grado*. Tyll of Innerfidelity** was known for not saying much about Grados. If we could corner Tyll, we may get him to admit that he didn't care much for Grados.

Most veterans today who wield Sennheisers, Audezes, HFMs, will admit that they had owned a higher-end Grado in the past or at the very least started with a Grado. The entry level Grados were (and still are) cheap, accessible, and didn't need an amp. I myself gave up on Grados in favor of Sennheiser after a period time only to come back. After so many years without Grados, I had realized that I missed Grados' punchy mid-bass, snappy transients, lively reactivity, crunchy mids, and woodie reverb/decay. Today I still have my JAR600, but it's always with a Grado next to it. The RS1X is always in my backpack.

Grado in my backpack

Read all about this DAC here: https://www.superbestaudiofriends.o...dac-for-750-that-stomps-most-modern-dacs.508/

I'm happy I now have modern instruments to measure this DAC, just out of curiosity. To summarize, I once owned this DAC, sold it, and regretted doing so. @Carlos CPA mentioned he was going to put a souped up one for sale at special member prices when he saw me mentioning my regret. I thought the price he was offering was too low, so I threw in a little extra. (Point is that we have a great community here. We have members who care about each other to the point of things not really being about profit or greed, keeping things in the community to deserving people who as passionate about stuff).



Anyway, this Sonic Frontiers SFD-1 MK2 looks to have the level 99 upgrade treatment based on the BOM from
https://partsconnexion.com/. For those who do not know, Chris Johnson who started Sonic Frontiers decade ago now heads up pcx. This specific unit sounds more resolving, more neutral, and less syrupy than the one I owned before which only had the level 1 upgrade and possibly an older iteration of the UltraAnalog DAC module.

Distortion Surface: old measurement, new approach

The following metric is typically included for amplifier manufacturers’ specifications:

THD+N < 0.05%

The above specification is incomplete, with operating conditions left out.

2Vrms 300 Ω load 1 KHz THD+N < 0.05%

This is a specification that allows replication of the measurement conditions exactly.

It is my long held opinion THD+N at a single operating point is nearly useless for assessing audio sound quality. Please see the following posts for reference:
https://www.superbestaudiofriends.o...-of-6-amps-thd-n-and-thd-specifications.6194/
https://www.superbestaudiofriends.o...thd-and-thd-n-specifications-and-graphs.5074/
https://www.superbestaudiofriends.o...distortion-vs-amplitude-a-visual-guide.12279/

So let me do a quick summary. A while ago, and this was on the tail end of the AmirNAD fad (SINAD at full scale, 1kHz stimulus, 20kHz bandwidth, 100/200kHz loads for SE/BAL respectively), Jason decided to hop on board because Texas Instruments had a new DAC chip that could do up to 120db AmirNAD. It wasn't an audio chip, but the given the DSP chops of MM, Dave, and Ivana, it wouldn't be much of a problem to get audio data into the chip. The chip in question was this: https://www.ti.com/product/DAC11001A



So I guess the story is that TI calls @schiit and tells him: Hey, we have this new B version that fixes the measured ultrasonic f'ery. Wanna try it out. Of course we know @schiit will not refuse, at least to try it. And thus voila, the MIL-B (or whatever it's going to be called). I asked Jason if I could borrow this because, you know, we like real science here. Actually exploring and learning new things is fun! Sticking to an old dogma is dumb (and yes, the THD+N cult has been around forever, read up on Doug Self)

So fast forward a bit, I pick up a Mjolnir 3 for myself and try out a few DACs to see which ones I preferred best, you know, the synergy thing. Turned out the DAC11001B based MIL-B was the winner. Not only that, but the MIL-B had been baking for a few weeks now. With a more resolving setup in front of me, I didn't realize how much it had changed.

iFi audio GO pod + IEMs = brilliant wireless sound on the GO! Plug a pair of ‘GO pod’ wearable Bluetooth DAC/amps into high-performance IEMs to make the best-sounding true wireless in-ear headphones in the world.


Above iFi’s ‘GO pod’ wearable Bluetooth DAC/headphone amp, connected to Symphonium Meteor IEMs

Southport, England – Joining iFi’s GO series of ultraportable headphone enhancers, the GO pod is a pair of wearable Bluetooth DAC/headphone amps designed to make any pair of corded in-ear monitors (IEMs) wireless. Given the quality of the GO pod’s circuitry, when combined with a well-chosen pair of high-performance IEMs, the resulting sound is far in advance of any ‘true wireless’ earbuds or Bluetooth headphones.

Using a pair of GO pods is simple. First, detach the cable from your favourite IEMs and connect the earpieces to the left and right pods. Then, pair the pods with your source device (a smartphone, for example) and hook the ergonomically designed ear loops behind your ears to ensure a comfortable fit… the result is unrivalled TWS (True Wireless Stereo) headphone sound.

https://www.schiit.com/products/mjolnir-3

Cat's outta the bag I guess. I got to hear this at the recent Schiit meet in Corpus. Didn't listen super long, so don't have a ton of impressions, but it was very fluid, smooth and resolving... I wanna say warm, like a souped up Jot 2, but please take that with a grain of salt because it was a while ago and my memory is hazy. But I came away impressed.



TomNC: This weighs 16 lbs. Highly interested in impressions of its performance with both dynamic and planar headphones, in particular, the moderately hard to drive LCD-4 (200 Ohm).

ColtMrFire: @purr1n was there, maybe he can chime in? Not sure if he got ears on it, or has had it for an extended listen.

Shanling ET-3 sitting on up of an Emotiva ERC-4


Well, I guess the ET-3 is it. And at $729, it's priced right! This is something that normal people can afford without eventually becoming 65 year old goofball incels disowned by their wife and kids. When I first saw the ET-3 at a distance, my magic eight ball foretold: IT WILL BE GOOD. First of all, I like the sound of top loaders. I noted that the ET-3 followed the top-loader philosophy of the ancient Shanling CDTs. A Rega Planet CDP which was also a top loader (with mechanism mods) sounded great, that is until my youngest shoved a carrot into it. Second, Shanling tended either dampen or massload their transports by design (something I've done extra as mods to with mediocre cheap CDTs). Although I wasn't sure back then, I expected Shanling to carry forth this approach. Turns out to be true. The ET-3 is a decent weight for its quarter form factor size. The chassis of the ET-3 is well dampened with a thud and doesn't ring. The ET-3 represents the best of what Chi-Fi has to offer. Quality at relative good value. And no, Chi-Fi isn't a bad word. If anything I think it's companies like Topping/SMSL and forums like ASR that have promoted the temple of SINAD which have ruined Chi-Fi's reputation in the past five years.

I could go and start with a preamble about the how and why of my falling in love with the Campfire Solaris, but that'd add at least a few more minutes' runtime to this whole mess so I'll cut to the part where I get offered a pair of Solarises for a ridiculously generous price. I turn this offer down because I'm trying to be responsible with my money. The guy who offered them to me says he understands and we agree that I'm to ping him when I feel I'm able to justify the expense; what he doesn't know is that I at this point am fully intending for him to find another buyer so that I need not be tempted to be dumb with my money.

This was in December of 2020.

I wanted to post this a while back. My first exposure to Texas Bourbon was a year ago at the Emotiva x Schiit event. At the Doubletree, I ordered a Garrison Brothers bourbon just to try something local (I had the waiter run down the list of bourbons they had). The one below (leftmost) is the regular Garrison Brothers, which was not as good as the one I tried. The one I tried was a special edition cask strength "Cowboy", which is now a year later like a million dollars (not worth that much, I'd pay $150, but not $400).

Just got the recently-announced Lumin U2 in for review. The U2 is solely a "streamer"; its function is to connect an upstream music server to a downstream DAC.

One of the nice things about the U2 is that it has two very useful new features that the U2 Mini and U1 don't have: an SFP-type optical transceiver port to allow connection via LC/LC optical fiber directly into the U2 from an upstream server (no need for potentially grungy and dirty copper Ethernet connections-gack! ), and a new "dedicated" USB port that is exceptionally quiet and...direct-coupled. This port's function is soley to connect to a USB DAC, rather than USB devices e.g. hard drives, flash media, etc.

Some pics:


I'm connecting to the U2 via LC/LC fiber from EtherREGEN in the remote server room, and the P1 with a USB cable.

It's only got about 70 hours or so on it, and it needs 500 hours to fully burn-in, but so far, I am very impressed. It's sounding very good, indeed.

More to come as I get more hours on it, stay tuned.

Standard Prologue
If you are unfamiliar with audio measurements please use a search engine with the query:
"audio measurements" or "audio measurement handbook"
Look for publications by Richard C. Cabot and also by Bob Metzler, both from Audio Precision. There are other useful publications as well. These will provide basic knowledge.
Interpretation of the following measurements is beyond the scope of technical measurements posts.

Notable highlights:
First, well done Doug and CeeTee! This is an incredible headphone amplifier.
Nearly perfect gain linearity spanning over 110 dB range in balanced input operation
± 1 dB gain linearity over 120 dB range in balanced input operation
SNR greater than 123 dB in balanced input operation
Excellent square wave response
Bandwidth: DC to greater than 168 KHz
Clarity and tube magic yet no tubes

Twelve years ago (and I can't believe it's been that long), a lot of headphones sounded like shit. To be precise, many had horrible treble peaks or irregularities that hurt my ears (and the ears of @Hands, @rhythmdevils, etc.). My reference back then were speakers that I had built that met a neutral target (neutral on-axis / B&K AES 1970 target at listening position), so many headphones left me scratching my head. Why the fuck is the treble so rough and peak I was thinking! I was avid Head-Fi poster back then trying to convince to fellow Head-Fiers what I heard was real. My approach ended up as this: https://www.head-fi.org/threads/headphone-csd-waterfall-plots.566929/